The present invention relates to compositions comprising an antagonist/inhibitor of a polynucleotide, said polynucleotide to be inhibited being capable of decreasing or suppressing expression of FZD3 (Frizzled-3) or a biologically active derivative thereof for use in treating or preventing bone disorders and/or cardiovascular disorders. Such bone disorders comprise, inter alia, osteoporosis, osteopenia, bone fracture, bone cancer, as well as impaired bone homeostasis. Cardiovascular diseases to be treated by the compounds of the present invention may be selected from the group consisting of infarction, stroke, hypertension, thrombosis, vascular stenosis, coronary syndromes, vascular dementia, heart failure, renal failure, stress-related carciovascular disorders, and atherosclerosis. Preferred compounds to be used in these medical interventions are antagonistic compounds, like nucleic acid molecules, directed to polynucleotides that are capable of decreasing or suppressing expression of FZD3 or a biologically active derivative thereof. An example of such a polynucleotide that needs to be antagonized is miR-31 or its 5′ or 3′ isoforms or variants. Also, the present invention relates to methods for and compositions for use in diagnosing bone disorders and/or cardiovascular disorders. Compounds to be used in these diagnostic methods may be compounds (like primers and probes) that are capable of detecting such a polynucleotide that is capable of decreasing or suppressing expression of FZD3 or a biologically active derivative thereof. miR-31 (or miR-31 or its 5′ or 3′ isoforms or variants) is, in accordance with this invention, a polynucleotide that is capable of decreasing or suppressing expression of FZD3.
Accumulation of damage in cells and tissues has been accepted as one of the major driving forces of aging and age related diseases (Kirkwood, Cell (2005), 120: 437-474). One of the repair systems on tissue level that counteracts this functional decline are adult stem and progenitor cells. Their ability to self-renew and differentiate is essential for homeostasis of tissues and organs. As adult human stem and progenitor cells with high differentiation potential have been identified in different tissues of the human body they would represent a pool of cells that should maintain high levels of tissue functionality. However, their function also declines with age (Rando, Nature (2006), 441: 1080-1086). The old systemic environment has been identified to contain factors that either fail to promote or actively inhibit successful tissue regeneration when tested in a parabiosis mouse model (Conboy, Nature (2005), 433: 760-764), while factors contained in the systemic environment of young animals promote successful tissue regeneration (Matsumoto, Eur Heart J (2009), 30: 346-355).
Visceral fat accretion is among the hallmarks of aging in humans (Huffman, Biochem Biophys Acta (2009), 1790: 1117-1123), while osteogenic differentiation potential of ASCs decreases with age. This decrease is not due to a loss of osteogenic precursors (Zhu, J Tissue Eng Regen Med (2009), 3: 290-301), suggesting that factors altering the cellular behaviour are involved. Furthermore, ASCs and endothelial cells are linked in vivo since preadipocytes within adipose tissue depots and endothelial cells exhibit a close relationships (Hausman, J Anim Sci (2004), 82: 925-934), supporting a paracrine relationship between these cell types.
However, the source of these factors altering the cellular behaviour was unknown so far and only scarce knowledge is available on the identity of these factors, where Wnt and TGF-β signalling seem to be involved (Carlson, Aging Cell (2009), 8: 676-689). Besides various glands, one source of secretion into the blood stream are endothelial cells per se and during older age, senescent endothelial cells, since they accumulate during aging in vivo, especially at sites of atherosclerosis (Erusalimsky, Handb Exp Pharmacol (2006), 213-248; Erusalimsky, Exp Physiol (2009), 94: 299-304); Minamino, Circ Res (2007), 100: 15-26). Several proteins that increase with senescence (Chang, Exp Cell Res (2005), 309: 121-136) have been identified, among them interleukin 8 that is found at up to 50-fold higher levels in the supernatants of senescent endothelial cells (Hampel, Exp Gerontol (2006), 41: 474-481).
One of the transport mechanisms in blood has been described: various factors are packaged into exosomes, membrane-coated particles that are secreted via exocytosis and play a role in cell-cell or organ-organ communication by fusion with cells of target tissues (Caby, Int Immunol (2005), 17: 879-887). Exosomes, 40-100 nm in size, are membrane vesicles of endosomal origin that are released into the extracellular environment. They can act on intercellular communication by allowing exchange of proteins, lipids, and also mRNA and miRNAs between cells (Valadi, Nat Cell Biol (2007), 9: 654-659; Viaud, PLoS One (2009), 4: e4942). The contained factors like miRNAs, mRNAs and proteins then influence the behaviour of the target cells. Examples are endothelial progenitor cell derived exosomes that induce angiogenesis in endothelial cells upon uptake (Deregibus, Blood (2007), 110: 2440-2448), endothelial-derived exosomes in patients with pulmonary arterial hypertension (Bakouboula, Am J Respir Crit Care Med (2008), 177: 536-543), ovarian carcinoma and glioblastoma cells that release exosomes and change the tissue microenvironment in favour of tumor progression (Keller, Cancer Lett (2009), 278: 73-81; Skog, Nat Cell Biol (2008), 10: 1470-1476). Especially exosomes released from tumour cells, which carry antigenic molecules recognized by T cells, has suggested as a cell free antigen source for anticancer vaccines (Escudier, J Transl Med (2005), 3: 10; Iero, Cell Death Differ (2008), 15: 80-88; Morse, J Transl Med (2005), 3: 9; Viaud, Horm Metab Res (2008), 40: 82-88; Viaud, PLoS One (2009), 4: e49429).
However, mechanisms and factors involved in tissue regeneration or in inhibiting the same are still poorly understood and influencing the impact of such factors on tissue regeneration is hardly possible.
This technical problem has been solved by the embodiments provided herein and the solutions provided in the claims.